1. Field of the Invention
The present invention relates generally to an apparatus and method of testing materials and, more particularly, to the testing of materials to determine surface characteristics and the effect thereof relative to the formation of a seal against such a surface.
2. State of the Art
In order to properly engineer or design a structure, mechanism, device or other component, it is necessary to have an understanding not only of a specific technological discipline (e.g., mechanical or electrical engineering) but also of the properties and characteristics of various materials which are available for construction of the resulting device. For example, it is desirable to understand strength related properties, such as the modulus of elasticity, yield strength, tensile strength and ductility for a given metal or alloy before utilizing such a material to form a structural member (e.g., a beam, truss, frame, shaft, etc.). Similarly, it is important to understand a material's electrical properties, such as its coefficient of conductivity (or resistivity), in designing, for example, an integrated circuit package. Other conventional material properties and characteristics which are often utilized in the engineering and designing of a particular device or component include, for example, thermal conductivity, coefficient of thermal expansion, density, as well as numerous other properties and characteristics.
Often the device being designed and manufactured is a complex structure meaning that multiple materials are being used and multiple components are being fitted together in a specific arrangement in order to achieve a desired result. Thus, it becomes even more important to understand the properties and characteristics of materials, not simply in isolation, but also in terms of compatibility with other materials as well as in terms of how the materials might react in potential situations not previously considered or analyzed.
Certain properties or characteristics of a given material may be known as a result of prior use or testing. For example, the exemplary material properties set forth above are often known, and often listed in standardized tables, for various materials including, for example, common metallic or alloyed materials. However, even having a basic understanding of the properties and characteristics of a given material, it can still be difficult to predict how a particular material may perform in a new application or environment. This may be particularly true in the case where multiple materials are being combined such as is the case with composite materials. Similarly, if a failure occurs in a device or assembly which includes several components and is formed of multiple materials, it can be difficult to determine which component or components and/or, which material or materials, ultimately led to the failure.
For example, if a seal, which is disposed between two components, fails to prevent fluid flow between the two components, it may not be immediately apparent whether the failure is due to an improper design or configuration of the seal or some other factor. In fact, oftentimes investigation must be made into the possibility of such other factors in order to more fully understand why a particular component or material performed in a particular manner.
In one particular example, as shall be discussed in further detail below, the failure of a seal element to prevent fluid flow between two adjacent components led to investigations regarding, among other things, advanced material properties and characteristics such as the occurrence of microcracking and/or crazing within various materials and the effect of such phenomena on the ability to of a material's surface to form an appropriate seal when abutted by the sealing element.
In conducting such investigations it was determined that existing testing equipment and methods were not adequate to provide the desired analysis. Thus, it was determined that it would be advantageous to provide a method and apparatus for testing materials to determine certain properties of materials, such as microcracking and crazing, and the effect of such phenomena under various circumstances.